Solar energy: what you need to know
Solar power is simply usable energy generated from the sun in the form of either electric or thermal energy. Solar energy is captured in a variety of ways, with the most common being a solar photovoltaic system, or PV system, that converts the sun’s rays into usable electricity. Aside from using photovoltaics to generate electricity, solar thermal energy, or concentrating solar power (CSP), is commonly used to heat indoor spaces or fluids. Residential and commercial property owners can install solar hot water systems and design their buildings with passive solar heating in mind to fully take advantage of the sun's energy with solar technology.
Types of solar energy systems
Interested in benefiting from solar power? Solar panels are installed at three main scales: residential, commercial, and utility. Homeowners can take advantage of residential-scale solar, typically in the form of rooftop solar or in ground-mounted solar installed in open land. Generally, residential solar systems are between 5 and 20 kilowatts (kW), depending on the size of the home.
Commercial solar energy projects are typically installed at a greater scale than residential solar. While individual installations can vary greatly in size and cost, commercial-scale solar arrays serve a consistent purpose: to provide on-site solar power to businesses and nonprofits. Finally, utility-scale solar projects are typically large-scale solar power plants that are several megawatts (MW) in size — utility-scale solar installations provide solar energy to a large number of utility customers.
For some solar shoppers who may not be able to install solar on their property due to cost or other factors, community solar is a viable solar option that more directly connects utility-scale solar energy projects to residential consumers. As such, community solar farms are typically built in central locations as opposed to on any single property. Subscribers (homeowners, renters, businesses, or non-profits) can join a community solar project to receive many of the benefits of solar power without installing solar panels on their property.
How do solar panels work?
A solar panel (also known as a solar module) consists of a layer of silicon cells, a metal frame, a glass casing unit, and wiring to transfer electric current from the silicon. Silicon (atomic #14 on the periodic table) is a nonmetal with conductive properties that allow it to absorb and convert sunlight into usable electricity. When light hits a silicon cell, the light causes electrons in the silicon to be set in motion, initiating a flow of electric current. This is known as the “photovoltaic effect,” and it describes the general functionality of solar panel technology.
The science of generating electricity with solar panels boils down to this photovoltaic effect. It was first discovered in 1839 by Edmond Becquerel and can be thought of as a property of specific materials (known as semiconductors) that allows them to create an electric current when they are exposed to sunlight.
The photovoltaic process works through the following broad steps:
- The silicon photovoltaic solar cell absorbs solar radiation
- When the sun’s rays interact with the silicon cell, electrons begin to move, creating a flow of electric current
- Wires capture and feed this direct current (DC) electricity to a solar inverter to be converted to alternating current (AC) electricity
A brief history of solar power
In 1954, Bell Labs developed the first silicon photovoltaic cell. Although solar energy had previously been captured and converted into usable energy through various methods, only after 1954 did solar power begin to become a viable source of electricity to power devices over extended periods of time. The first solar cells converted solar radiation to electricity at an efficiency of 4 percent — for reference, many widely available solar panels today can convert sunlight to solar power at above 20 percent efficiency, a number constantly on the rise. Although solar energy adoption was slow at first, a number of state and federal incentives and policies contributed to driving down the cost of solar far enough to become more widely adopted.
The cost of solar energy
Concurrent with an increase in solar efficiency, the cost of solar panels has fallen substantially. In the last decade alone, the cost of a solar panel installation fell over 70 percent, and many industry experts predict that prices will continue to fall in the years to come.
Additionally, depending upon where you live, several rebates or incentives for solar power may contribute towards lowering the cost of solar energy even further. Nationwide, the federal Investment Tax Credit (ITC) is one of the primary incentives available to anyone interested in solar energy, as it allows you to deduct 30 percent of the cost of installing a solar array system from your federal taxes. This incentive won't last forever: in 2033, the federal ITC steps down to 26% and it will go away completely for residential solar installations in 2035. Many states and utilities offer further incentives (such as net metering) in addition to the federal ITC, dropping the cost of solar power even further.
Interested in seeing what solar will cost you? Try our solar calculator for a quick estimate.
Solar energy is a renewable power source
Solar energy is a clean, inexpensive, renewable power source that is harnessable nearly everywhere in the world — any point where sunlight hits the surface of the earth is a potential location to generate solar power. And since solar energy comes from the sun, it represents a limitless source of power. Renewable energy technologies generate electricity from resources that are infinite.
Compare producing electricity with renewable resources to fossil fuels: it took hundreds of thousands of years for oil, gas and coal to form. So, every time one of those resources is burned to create electricity (and emissions!), that finite resource is moved marginally closer to depletion. Using a renewable resource — such as wind, solar and hydropower — to generate electricity does not deplete that resource. There will always be consistent sunlight shining on Earth's surface, and after turning sunlight into electricity, there is still an infinite amount of sunlight to turn into electricity in the future. That is what makes solar power, by nature, renewable energy.
While the current electricity mix in the United States is still made up largely of fossil fuels like oil and gas, renewable energy sources like solar are steadily becoming a larger part of the country's energy profile as the cost becomes more competitive.
Should you go solar?
When it comes to installing solar panels and switching to a more eco-friendly energy source, there’s not a one-size-fits-all approach. There are several questions you should ask to help determine if your home or business is a good candidate for solar:
- How much electricity do you consume and how much does electricity cost in your area? The more electricity you use, and the more you pay for it, the more you’ll save by going solar.
- Do you own your home? If you live in a multi-family home or rent the property, it will be much more difficult to install solar than if you own a single-family home.
- Is your roof good for solar? The ideal roof for solar would be one that’s pretty spacious, is in good condition, isn’t too complex, is southern-facing, and receives plenty of direct sunlight. If not, you should consider if you have land space for a ground-mounted system.
- Are there local, reputable solar companies in your area that can perform the installation? If you don’t live in an area with multiple installers competing for your business, you may end up paying a premium.
- What incentives are available where you live? Local and state incentives could end up saving you thousands of dollars on your solar energy system, significantly shortening your payback period.
If some of these characteristics aren’t aligned with your situation but you’re still interested in going solar, read our article about if solar is right for you for more information on whether you’re a good fit.
What to know about the solar industry
According to the Solar Energy Industries Association (SEIA), solar capacity has grown about 33 percent, on average, over the past decade. In fact, the Department of Energy (DOE) reports that the United States has about 97.2 gigawatts (GW) of installed solar power capacity to date — enough to provide clean energy to about 18 million homes.
As solar capacity continues to grow, so too does the need for new solar jobs. From installing to manufacturing to performing operations and maintenance to educating consumers, there are a number of things you could be doing as a solar industry employee! As of December 2021, the solar industry supported 255,037 jobs based on data from the Interstate Renewable Energy Council (IREC)’s National Solar Jobs Census — a 9.2% increase from 2020.
The rapid proliferation of solar power nationwide and globally has also led to parallel growth in several adjacent areas. Notably, solar battery systems, electric vehicles, and heat pumps are all sectors poised to explode alongside the solar industry by augmenting the benefits of solar.
Want to support the solar industry? Consider switching your electricity generation source to solar power! Whether you install solar panels on your home or business, or subscribe to a community solar farm, you’ll be adding to the total capacity of installed solar energy, while helping grow the clean energy economy.
